William Boddy, who has died aged 98, was the editor of Motor Sport magazine from 1936 to 1991. His career spanned 81 years in total; he wrote his first piece for Motor Sport in 1930 and filed his final column for the magazine a week before he died, still working on a typewriter and making copious handwritten corrections to his copy.

Boddy – known as Bill, or as "WB" to generations of devoted readers – was possibly the longest-serving working journalist in Britain, and probably the most important single figure in the development of the vintage and classic car movement in Britain. He championed the cause of older vehicles through Motor Sport's pages when few seemed to be interested during the new car boom of the 1950s and 60s.

Boddy loved Brooklands in Weybridge, Surrey, the world's first purpose-built motor-racing circuit, which he first visited as a boy in 1926. He had an encyclopedic knowledge of its history that was unsurpassed. His first article for Motor Sport was on the history of the circuit and he later wrote the definitive book on the subject. As early as 1934, he organised an event there for historic Edwardian racers. When the track was declared an industrial area in 1946, Boddy formed the Brooklands Society, which helped ensure that original buildings and the surviving parts of the track became listed.

Boddy was born in London. His father was killed in the first world war. On childhood holidays in Wales he had the opportunity to ride in limousines belonging to a wealthy relative, promoting his interest in motoring. He always loved facts and details and as a schoolboy in the 20s wrote endlessly to the motoring periodicals of the time pointing out mistakes. He even managed to get himself, aged 14, a 100mph demonstration ride in a new Mercedes. His first editorial position – after a brief stint as an assistant in a motorcycle shop – was on Brooklands Track and Air magazine, for which he wrote road tests, despite not yet having a driving licence: he wrote the tests by observing the cars' responses from the passenger seat.

After going freelance in the mid-30s, Boddy did most of his work for Motor Sport, a 10-year-old title that was rapidly going bankrupt. He was owed so much money when the magazine was taken over by the eccentric Wesley J Tee in 1936 that the new publisher promised to make the 23-year-old editor as long as he kept away from the creditors' meeting. Usually on the end of a telephone, Boddy somehow managed to keep the title going in his spare time throughout the second world war while working in the RAF, despite the fact that there was no motor racing or new cars to report on.

In the 50s and 60s, Boddy built up Motor Sport, with its distinctive green front cover, into an influential title despite having no particular plan. "I just thought I'd write about anything that interested me," he explained "Readers seemed to like it." The tradition of using only initials rather than authors' bylines was maintained on the insistence of Tee, who owned the title until his death in 1996.

Decades before there were dedicated classic car magazines, Motor Sport was a monthly bible for enthusiasts, stuffed with adverts for ageing exotica that could be bought for a few hundred pounds. But it was also the most influential magazine of its type in Europe, and the place to read about motor racing and new cars. Boddy wrote extremely frank road tests of the latest models that sometimes got him into trouble with several manufacturers. He also covered general motoring issues, most memorably campaigning against the introduction of the 70mph national speed limit in the 1960s. He was not afraid of unpopular causes and was a lone but prophetic voice championing the cause of the VW Beetle amid the anti-German atmosphere of the 50s.

Boddy went on 39 London-to-Brighton veteran car runs; helped form the 750 Motor Club, promoting low-cost motor sport for Austin Seven drivers; was a founder member of the Vintage Sports-Car Club; and promoted the 500cc racing movement, a low-budget form of motor sport which lead to Britain's domination of Formula 1. He was appointed MBE for services to sports journalism in 1997.

He married Winifred Holbrook in 1944. She died in 1998. Their three daughters survive him.

• William Charles Boddy, journalist, born 22 February 1913; died 7 July 2011